For example, Patent Literature 1 below discloses “a lithium secondary battery employing a carbon material as a negative electrode support material and, as an electrolyte solution, an organic electrolyte solution in which a lithium salt as an electrolyte is dissolved in an organic solvent”. Patent Literature 1 discloses that “the amount of the lithium salt in the electrolyte solution is set at 0.5 millimoles or less per 1 gram of the carbon material”. Other prior art documents about lithium secondary batteries include Patent Literatures 2 through 6, for example.